Why should vegetables be blanched before freezing?

Foods such as fruits and vegetables contain enzymes that cause color and flavor changes. The activity of enzymes is temperature dependent. This activity can be destroyed at boiling temper-atures but still be active at extremely cold temperatures. For vegetables, blanching for a brief amount of time will inactivate these enzymes and result in a higher quality food. Vegetables, in particular, are heat blanched with water or steam. Blanching will also destroy surface microorganisms. The food will also shrink slightly for increased freezer storage. The length of time and blanching method depends on the vegetable. It is important to follow recommended blanching times. After blanching, the vegetable must be cooled quickly to stop the cooking process. Plunge into ice water for the same amount of time as blanching.